Mr Nash said the rail line needed to be restored and used because rail was a vital piece of the East Coast's infrastructure and it was something Labour was committed to re-opening if it had control of Treasury.
"If we don't get it up and running it will reduce our economic development," he said, adding there was unlikely to be any serious investment in the East Coast by producers if there was not a strong and efficient way to get it to port.
The proposed cycle trail would run along the path of the mothballed rail line. Mr Walford likened the potential to that of the Otago Rail Trail which was developed after that line closed in 1990.
Running for 150km between Middlemarch and Clyde, the trail attracted about 10,000 recreational cyclists every year and generated $16 million in income last year.
Mr Walford said Hawke's Bay and Gisborne were in the position to pursue that sort of business.
If the reaction from the public was strong and positive, Mr Walford said he would establish a trust to champion the idea and seek funding for a feasibility study. Part of that study would involve whether the rail link could ever re-open.
The cycle trail could potentially be composed of heavy matting topped with limestone along the track, which would remain in place.
Mr Walford said the tourism component was strong.
"Up and down the country, small communities are being rejuvenated and transforming themselves as more domestic and international cycle tourists visit recently built cycleways."
He said each cycleway had unique features, and the Sunrise Rail Trail would be no different.
Mr Walford said he believed that with the unspoiled scenery along the stretch, the low-impact form of tourism could benefit smaller communities.
He said there were a number of small villages along the way such as Kotemaori, Raupunga and Waikouau, as well as marae which could provide a cultural experience.
The Hawke's Bay Tourism stance was one of support for tourism enterprises in the region and effectively supported the cycleway plan. But a spokesperson said while it was a good idea there would have to be realistic expectations about it and the infrastructure must be sound. "Providing it is all fleshed out, we are supportive."
The Hawke's Bay Regional Council is, however, continuing to support a scheme to get the closed line back into regular service.
The regional council has earmarked just under $5.5 million in its draft annual plan to re-establishing the rail link which was mothballed in December 2012.
That investment is dependent on KiwiRail and the Government funding the line's re-opening.
Transport Minister Gerry Brownlee has indicated the Government is not interested in paying for the work needed to bring it back up to scratch.